Japanese Association Research Articles

Identifying Subgroups with Differential Responses to Amiodarone among Cardiac Arrest Patients with a Shockable Rhythm at Hospital Arrival using the Machine Learning Approach.

There are few reports of studies on the differential effects of amiodarone among out-of-hospital cardiac arrest (OHCA) patients with a shockable rhythm at hospital arrival. The present study aimed to investigate the clinical heterogeneity of OHCA patients with a shockable rhythm upon hospital arrival and to identify subgroups with differential responses to amiodarone, using a machine learning approach. We used the Japanese nationwide OHCA registry of the Japanese Association for Acute Medicine for this study; data from OHCA patients with a shockable rhythm at hospital arrival were included in the analyses. The primary outcome was a favorable neurological outcome at 30 days. We developed a scoring system by the weighting method with logistic likelihood loss to identify patient subgroups showing differential effects of amiodarone from the point of view of the neurological outcome and survival at 30 days. Among the 68,111 cases of OHCA in the registry, the data of 2333 OHCA patients with an initial shockable rhythm at hospital arrival were analyzed. The developed score identified higher age, longer interval between the call to the emergency medical service and hospital arrival, absence of a "witness", no defibrillation prior to hospital arrival, hypothermia at hospital arrival, and pre-hospital epinephrine administration as variables that were significantly associated with a beneficial effect of amiodarone. Based on the results of the developed scoring system, 47% (1107/2333) of the patients were considered to greatly benefit from amiodarone administration, whereas 53% (1226/2333) of patients were considered to not benefit from amiodarone administration. The effect of amiodarone on the neurological outcome at 30 days varied significantly among the subgroups identified by the developed score ( : 1.07 [95% confidence interval (CI): 0.99-1.13], p = 0.005). We successfully developed a model that could discriminate between OHCA patients with an initial shockable rhythm at hospital arrival who would benefit or not benefit from the administration of amiodarone in terms of the neurological outcome at 30 days. There was clinical heterogeneity among OHCA patients with a shockable rhythm in terms of their response to amiodarone.

Risk factors and clinical significance of lower perigastric lymph node metastases in Siewert type II and III esophagogastric junction adenocarcinoma: a retrospective cohort study

BackgroundNo consensus has been concluded with regarding to the scope of lymph node (LN) dissection for Siewert type II and III adenocarcinoma of the esophagogastric junction (AEG). This study aimed to explore risk factors for lower perigastric LN (LPLN) metastases (including no. 4d, 5, 6, and 12a LN stations) and analyze the indications for LPLN dissection.MethodsIn total, 302 consecutive patients with Siewert type II and III AEG who underwent total gastrectomy (TG) were enrolled. The logistic regression model was used to perform uni- and multivariate analyses of risk factors for LPLN metastases. Kaplan–Meier curves were used for survival analysis, and log-rank tests were used for group comparisons. Basing on the guidelines of Japanese Gastric Cancer Association, the LN metastases (LNM) as well as the efficiency index (EI) of each LN station was further evaluated.ResultsThe independent risk factors for LPLN metastases in patients with Siewert type II and III AEG were distance from the esophagogastric junction (EGJ) to the distal end of the tumor (> 4.0 cm), preoperative carcinoembryonic antigen (CEA) ( +), pT4 stage, and HER-2 ( +). LPLN metastases was an independent risk factor for overall survival following TG. The LNM and EI of LPLN were 8.6% and 2.31%, respectively. The LNM of LPLN > 10% under the stratification of the distance from the EGJ to the distal end of the tumor (> 4.0 cm), pT4, preoperative CEA ( +), and HER-2 ( +) exhibited EI values of 3.55%, 2.09%, 2.51%, and 3.64%, respectively.ConclusionsLPLN metastases was a malignant factor for the prognosis of patients with Siewert type II and III AEG. For patients with preoperative CEA ( +), pT4 stage, HER-2 ( +), and the distance from the EGJ to the distal end of the tumor (> 4.0 cm), TG with LPLN dissection is prioritized for clinical recommendation.

Proposal and Validation of a Clinically Relevant Modification of the Japanese Association for Acute Medicine Disseminated Intravascular Coagulation Diagnostic Criteria for Sepsis.

Japanese Association for Acute Medicine (JAAM) disseminated intravascular coagulation (DIC) criteria were launched nearly 20 years ago. Following the revised conceptual definition of sepsis and subsequent omission of systemic inflammatory response syndrome (SIRS) score from the latest sepsis diagnostic criteria, we omitted the SIRS score and proposed a modified version of JAAM DIC criteria, the JAAM-2 DIC criteria. To validate and compare performance between new JAAM-2 DIC criteria and conventional JAAM DIC criteria for sepsis. We used three datasets containing adult sepsis patients from a multicenter nationwide Japanese cohort study (J-septic DIC, FORECAST, and SPICE-ICU registries). JAAM-2 DIC criteria omitted the SIRS score and set the cutoff value at ≥3 points. Receiver operating characteristic (ROC) analyses were performed between the two DIC criteria to evaluate prognostic value. Associations between in-hospital mortality and anticoagulant therapy according to DIC status were analyzed using propensity score weighting to compare significance of the criteria in determining introduction of anticoagulants against sepsis. Final study cohorts of the datasets included 2,154, 1,065, and 608 sepsis patients, respectively. ROC analysis revealed that curves for both JAAM and JAAM-2 DIC criteria as predictors of in-hospital mortality were almost consistent. Survival curves for the anticoagulant and control groups in the propensity score-weighted prediction model diagnosed using the two criteria were also almost entirely consistent. JAAM-2 DIC criteria were equivalent to JAAM DIC criteria regarding prognostic and diagnostic values for initiating anticoagulation. The newly proposed JAAM-2 DIC criteria could be potentially alternative criteria for sepsis management.

External Validation of Updated Prediction Models for Neurological Outcomes at 90 Days in Patients With Out-of-Hospital Cardiac Arrest.

Few prediction models for individuals with early-stage out-of-hospital cardiac arrest (OHCA) have undergone external validation. This study aimed to externally validate updated prediction models for OHCA outcomes using a large nationwide dataset. We performed a secondary analysis of the JAAM-OHCA (Comprehensive Registry of In-Hospital Intensive Care for Out-of-Hospital Cardiac Arrest Survival and the Japanese Association for Acute Medicine Out-of-Hospital Cardiac Arrest) registry. Previously developed prediction models for patients with cardiac arrest who achieved the return of spontaneous circulation were updated. External validation was conducted using data from 56 institutions from the JAAM-OHCA registry. The primary outcome was a dichotomized 90-day cerebral performance category score. Two models were updated using the derivation set (n=3337). Model 1 included patient demographics, prehospital information, and the initial rhythm upon hospital admission; Model 2 included information obtained in the hospital immediately after the return of spontaneous circulation. In the validation set (n=4250), Models 1 and 2 exhibited a C-statistic of 0.945 (95% CI, 0.935-0.955) and 0.958 (95% CI, 0.951-0.960), respectively. Both models were well-calibrated to the observed outcomes. The decision curve analysis showed that Model 2 demonstrated higher net benefits at all risk thresholds than Model 1. A web-based calculator was developed to estimate the probability of poor outcomes (https://pcas-prediction.shinyapps.io/90d_lasso/). The updated models offer valuable information to medical professionals in the prediction of long-term neurological outcomes for patients with OHCA, potentially playing a vital role in clinical decision-making processes.

Is there any difference between Eastern and Western clinical practice guidelines in management of gastric cancer?

Gastric cancer (GC) has been known as one of the most common causes of cancer mortality both in Western and Eastern countries. However, there might be differences between how it is managed in different countries. Thus, we aimed to investigate these differences. The most well-known clinical guidelines in field of GC management including Korean GC Association (KGCA), Japanese GC Association (JGCA), National Comprehensive Cancer Network (NCCN), European Society for Medical Oncology (ESMO), British Society of Gastroenterology (BSG), and National Institute for health and Care Excellence (NICE) have been reviewed. The contents of these guidelines were categorized under eight headings including (1) genetic predisposition, (2) prevention, (3) management of gastric polyp, atrophy, dysplasia and metaplasia, (4) diagnosis, (5) pathology and molecular biology, (6) treatment, (7) supportive and palliative care, and (8) follow up. Difference in each section was discussed. Considering KGCA and JGCA as Eastern and NCCN, ESMO, BSG, and NICE as Western guidelines, it is revealed that both sets of guidelines share common practices such as prioritizing comprehensive diagnostic evaluations, personalizing treatment plans, and palliative care. However, main differences can be seen in treatment regimens, the adoption of newer therapies like immunotherapy, and the utilization of emerging techniques such as HIPEC. These differences reflect the diverse clinical landscapes, research focuses, and healthcare systems within these regions.

A Lower Prevalence of Central Nervous System and Higher Prevalence of Cardiac Symptoms Characterises Indian Patients with Thyrotoxic Storm: A Retrospective Analysis.

Thyroid storm is an uncommon but life-threatening presentation of thyrotoxicosis with a mortality rate of 10%. Our objective was to study the demographics, clinical and biochemical characteristics, and outcomes of inpatients diagnosed with thyroid storm in the Indian context. This retrospective study was conducted by analysing the institutional electronic medical records (EMR) of all patients admitted with thyroid storm from 2004 to 2020 with a Burch-Wartofsky score (BWS) of ≥45. Thirty-five patients with a BWS ≥45 were included, of whom 71.4% were women, with a mean age of 44.9 ± 10.2 years. 43% did not have any prior history of thyrotoxicosis. Graves' disease was the most common underlying aetiology (71.4%), followed by toxic multinodular goitre (14.3%). Cardiovascular (94.3%) and gastrointestinal-hepatic dysfunction (88.6%) were the most common clinical manifestations. Features of Central nervous system (CNS) dysfunction were seen in only 42.3% of patients diagnosed with a thyroid storm. The Japanese Thyroid Association (JTA) criteria diagnosed only 26 patients (74.3%) with "definite" thyroid storm. The mortality rate was 8.6%, and all three patients expired within 48 hours of admission. Nearly one in every two patients with thyroid storm had previously undiagnosed thyrotoxicosis. Toxic multinodular goitre is a notable aetiology in Indians. Features of CNS dysfunction, considered relatively specific for thyroid storm, were less prominent in our series. The JTA criteria might alter the classification of some patients diagnosed with a thyroid storm, when compared to the BWS score due to fewer CNS features among Indian patients.

Medical researchers’ perceptions regarding research evaluation: a web-based survey in Japan

ObjectivesJapanese medical academia continues to depend on quantitative indicators, contrary to the general trend in research evaluation. To understand this situation better and facilitate discussion, this study aimed to examine...

Adjuvant and post-recurrent treatment patterns in patients with resectable gastric cancer in Japan: a retrospective database cohort study

BackgroundThis study examined temporal shifts in adjuvant therapy patterns in Japanese patients with resectable gastric cancer (GC) and treatment patterns of first-line and subsequent therapy among those with recurrent disease.MethodsThis retrospective analysis of hospital-based administrative claims data (April 1, 2008 to March 31, 2022) included adults (aged ≥ 20 years) with GC who started adjuvant therapy on or after October 1, 2008 (adjuvant cohort) and patients in the adjuvant cohort with disease recurrence (recurrent cohort), further defined by the time to recurrence (≤ 180 or > 180 days after adjuvant therapy).ResultsIn the adjuvant cohort (n = 17,062), the most common regimen during October 2008–May 2016 was tegafur/gimeracil/oteracil potassium (S-1; 95.7%). As new standard adjuvant regimen options were established, adjuvant S-1 use decreased to 65.0% and fluoropyrimidine plus oxaliplatin or docetaxel plus S-1 use increased to 15.0% and 20.0%, respectively, in September 2019–March 2022. In the recurrent cohort with no history of trastuzumab/trastuzumab deruxtecan treatment (n = 1257), the most common first-line regimens were paclitaxel plus ramucirumab (34.0%), capecitabine plus oxaliplatin (CapeOX; 17.0%), and nab-paclitaxel plus ramucirumab (10.1%) in patients with early recurrence, and S-1 plus oxaliplatin (26.3%), S-1 plus cisplatin (15.3%), CapeOX (14.0%), S-1 (13.2%), and paclitaxel plus ramucirumab (10.8%) in those with late recurrence.ConclusionsThis study demonstrated temporal shifts in adjuvant treatment patterns that followed the establishment of novel regimens, and confirmed that post-recurrent treatment patterns were consistent with the Japanese Gastric Cancer Association guideline recommendations.

Lack of women physician representation in the Japanese Society of Hospital General Medicine.

The increasing number of women physicians is in contrast to their underrepresentation in academic positions and professional associations. This study aimed to evaluate the status of women physicians in the Japanese Society of Hospital General Medicine (JHGM) based on society membership, board membership, and annual meeting authorship. A cross-sectional analysis was conducted. Information on women physicians, society and board membership, and annual meeting authorship was collected. Data from the Japanese Primary Care Association (JPCA) served as the control. The gender of authors with accepted abstracts in the JHGM and JPCA annual meetings was determined by name or Internet search. In the JHGM, 14.2% of members were women physicians, compared to 19.1% in the JPCA (p < 0.001). None of the 21 JHGM board members were women, compared to 20.5% in the JPCA (p < 0.001). The average number of years of experience was significantly higher for the JHGM board members than for the JPCA board members (37.0 vs. 28.1 years, p < 0.001). Women first authors in the 2022-2023 JHGM meeting comprised 17.9%, significantly lower than the 28.4% in the 2023 JPCA meeting (p = 0.002). Similar patterns were seen for women last authors (6.0% in the JHGM vs. 18.8% in the JPCA, p < 0.001) and women chairpersons (17.9% in the JHGM vs. 40.3% in the JPCA, p = 0.036). The JHGM has low women representation in society and board membership, and annual meeting authorship. Strategies are needed to enhance diversity and inclusion by increasing women's participation and leadership in the JHGM.

Impact of Sex Differences on Clinical Outcomes in Patients Following Primary Revascularization for Acute Myocardial Infarction - Insights From the Japanese Nationwide Registry.

Women with acute myocardial infarction (AMI) often present a worse risk profile and experience a higher rate of in-hospital mortality than men. However, sex differences in post-discharge prognoses remain inadequately investigated. We examined the impact of sex on 1-year post-discharge outcomes in patients with AMI undergoing percutaneous coronary intervention. We extracted patient-level data for the period January 2017-December 2018 from the J-PCI OUTCOME Registry, endorsed by the Japanese Association of Cardiovascular Intervention and Therapeutics. One-year all-cause and cardiovascular mortality and major adverse cardiovascular events were compared between men and women. In all, 29,856 AMI patients were studied, with 6,996 (23.4%) being women. Women were significantly older and had a higher prevalence of comorbidities than men. Crude all-cause mortality was significantly higher among women than men (7.5% vs. 5.4% [P<0.001] for ST-elevation myocardial infarction [STEMI]; 7.0% vs. 5.2% [P=0.006] for non-STEMI). These sex-related differences in post-discharge outcomes were attenuated after stratification by age. Multivariate analysis demonstrated an increase in all-cause mortality in both sexes with increasing age and advanced-stage chronic kidney disease (CKD). Within this nationwide cohort, women had worse clinical outcomes following AMI than men. However, these sex-related differences in outcomes diminished after adjusting for age. In addition, CKD was significantly associated with all-cause mortality in both sexes.

Performance of a Large Language Model on Japanese Emergency Medicine Board Certification Examinations.

Emergency physicians need a broad range of knowledge and skills to address critical medical, traumatic, and environmental conditions. Artificial intelligence (AI), including large language models (LLMs), has potential applications in healthcare settings; however, the performance of LLMs in emergency medicine remains unclear. To evaluate the reliability of information provided by ChatGPT, an LLM was given the questions set by the Japanese Association of Acute Medicine in its board certification examinations over a period of 5 years (2018-2022) and programmed to answer them twice. Statistical analysis was used to assess agreement of the two responses. The LLM successfully answered 465 of the 475 text-based questions, achieving an overall correct response rate of 62.3%. For questions without images, the rate of correct answers was 65.9%. For questions with images that were not explained to the LLM, the rate of correct answers was only 52.0%. The annual rates of correct answers to questions without images ranged from 56.3% to 78.8%. Accuracy was better for scenario-based questions (69.1%) than for stand-alone questions (62.1%). Agreement between the two responses was substantial (kappa = 0.70). Factual error accounted for 82% of the incorrectly answered questions. An LLM performed satisfactorily on an emergency medicine board certification examination in Japanese and without images. However, factual errors in the responses highlight the need for physician oversight when using LLMs.

Fourth national Japanese antimicrobial susceptibility pattern surveillance program: Bacterial isolates from patients with complicated urinary tract infections

IntroductionAntimicrobial susceptibility patterns of bacterial pathogens isolated from patients with complicated urinary tract infections were analyzed using the national surveillance data, comprising 793 bacterial strains from eight clinically relevant species. Materials and methodsData were collected for the fourth national surveillance project from July 2020 to December 2021 by the Japanese Society of Chemotherapy, the Japanese Association for Infectious Disease, and the Japanese Society of Clinical Microbiology. Surveillance was supervised with the cooperation of 43 medical institutions throughout Japan. ResultsFluoroquinolone required a minimum inhibitory concentration (MIC) of 2–64 mg/L to inhibit the 330 tested Escherichia coli strains. The proportion of levofloxacin-resistant E. coli strains increased from 28.6% in 2008 to 29.6% in 2011, 38.5% in 2015, and 44.5% in 2021. The proportion of levofloxacin-resistant strains of Pseudomonas aeruginosa also increased from previous survey results, showing a continuing downward trend. Conversely, the proportion of levofloxacin-resistant strains of Enterococcus faecalis decreased relative to previous reports. Neither multidrug-resistant P. aeruginosa nor carbapenem-resistant Enterobacteriaceae were detected. For methicillin-resistant Staphylococcus aureus (MRSA), the proportion of vancomycin-susceptible strains (MIC of 2 μg/mL) decreased from 14.7% to 7.7%. DiscussionBacterial strains that produced extended-spectrum β-lactamase included E. coli (82/330 strains, 24.8%), Klebsiella pneumoniae (11/68 strains, 16.2%), and Proteus mirabilis (4/26 strains, 15.4%). As compared to previous surveillance reports, these strains showed an increase in proportion over the years.

모리사키 가즈에(森崎和江)의 작품에 나타난 식민지 ‘대구’의 공간표상 - 『경주는 어머니가 부르는 소리: 나의 원향』을 중심으로 -

모리사키 가즈에(森崎和江)의 작품에 나타난 식민지 ‘대구’의 공간표상 - 『경주는 어머니가 부르는 소리: 나의 원향』을 중심으로 -

On The 65th Annual Meeting of the Japanese Association of Educational Psychology (JAEP)

On The 65th Annual Meeting of the Japanese Association of Educational Psychology (JAEP)

Pushing the Boundaries: Societies as Catalysts for Advancing Coronary Surgery

Coronary artery disease (CAD) stands as the prevailing global cause of death, and coronary artery bypass grafting (CABG) remains the optimal revascularization method for severe CAD. While surgical management has progressed significantly, the implementation of these advancements requires acceleration. The impetus for this acceleration can be bolstered through specialized coronary surgery societies, which can concentrate research efforts, synthesize evidence, and contribute to the formulation of practice guidelines. Cross-continental collaborations among national and international societies, such as the International Society for Coronary Artery Surgery, Japanese Association for Coronary Artery Surgery, and Society of Coronary Surgeons (India), can address knowledge gaps, drive innovation, standardize training, and improve adherence to practice guidelines. Dedicated coronary societies have the potential to revolutionize coronary surgery and enhance patient outcomes.

Women's career development through everyday life in post‐war Japan: Survey of the Shufuren (the Japanese Association of Consumer Organizations)

AbstractThis paper explores the career development process of women in postwar Japan who belonged to the Shufuren (the Association of Consumer Organization), the homemakers' federation, and who became experts in everyday life through studying and researching to improve their lives. It analyzes the organizational chart, hours and fundings for activities, details of activities, formation of the cooperative relationships, and career development of the leaders. The women who gathered at the Shufuren studied and researched the issues that arose in daily lives. By accumulating survey and research data and presenting scientific evidence, they made requests and proposals for improvements to the Diet, governments, and industries. Through these activities, they contributed to establish laws and systems protecting consumer rights. The women also developed partnerships with other civic groups in sharing current social issues. They expanded the circle of the movement and asserted their demands to the Diet, government agencies, industries, and the public. The members grew as experts in everyday life by steadily building their careers with passion for daily activities. Their activities were not limited to the Shufuren; some women went beyond the Shufuren to become leaders of organizations. Conventionally, homemakers are viewed as not having career development aspirations. When discussing women's career development in Japan, attention has focused on career development through work and balancing work and family life. However, the activities and steps taken by the female members of the Shufuren to improve their lives should also be considered a form of career development.

Abstracts of the 82nd Annual Meeting of the Japanese Cancer Association; 2023 September 21-23; Yokohama, Japan.

Abstracts of the 82nd Annual Meeting of the Japanese Cancer Association; 2023 September 21-23; Yokohama, Japan.

A survey of environmental sustainability in Japanese dialysis facilities.

Dialysis practice has a particularly high environmental impact, including responsible for carbon emissions and climate change. Insufficient research has been conducted on environmental sustainability activities in dialysis therapy in Japan. We conducted an online Green Survey comprising 30 question items based on a previously conducted survey in Australia. Between August and September 2023, this was sent to members of the Japanese Association of Dialysis Physicians, including hospital and clinic physicians, working across 885 dialysis facilities in Japan. In total, 255 (29%) facilities responded to the survey. More than half of the facilities (n = 157; 61.6%) responded that they did not have a strategy, policy, or action plan for environmental sustainability. In four-fifths of the facilities (n = 208; 81.6%), no "green team" or committee had been formed to promote environmental protection. By contrast, most of the surveyed facilities had emergency strategies for natural disasters, such as covering for patient visits and staff commuting during extreme weather conditions (n = 169; 66.3%), water shortages (n = 159; 62.4%), and power outages (n = 188; 73.7%). Following the UK, Australia and New Zealand, and Portugal, this is the fourth Green Survey to be conducted, and the first on environmental sustainability among kidney health-care providers in Japan. The results indicated that daily activities for environmental protection are still lacking at many facilities, even though the management of dialysis treatment during a natural disaster is well conducted.

Cross-sectional analysis of financial relationships between board certified allergists and the pharmaceutical industry in Japan

BackgroundFinancial interactions between pharmaceutical companies and physicians lead to conflicts of interest. This study examines the extent and trends of non-research payments made by pharmaceutical companies to board-certified allergists in Japan between 2016 and 2020.MethodsA retrospective analysis of disclosed payment data from pharmaceutical companies affiliated with the Japanese Pharmaceutical Manufacturers Association was conducted. The study focused on non-research payments for lecturing, consulting, and manuscript drafting made to board-certified allergists from 2016 to 2020. We performed descriptive analyses on payment data. Trends were analyzed using generalized estimating equation models.ResultsOf the 3,943 board-certified allergists, 2,398 (60.8%) received non-research payments totaling $43.4 million over five years. Lecturing fees comprised 85.7% ($37.2 million) of the total payment amounts. For allergists who received at least one payment, the median amount per allergist was $3,106 (interquartile range: $966 – $12,124), in contrast to a mean of $18,092 (standard deviation: $49,233) over the five-year span. The top 1% and 10% of these allergists accounted for 20.8% and 68.8% of all non-research payments, respectively. The annual payment amounts significantly increased by 7.2% annual increase (95% CI: 4.4 – 10.0%, p < 0.001) each year until 2019, but saw a significant decrease in 2020 amid the COVID-19 pandemic.ConclusionThe majority of allergists received non-research payments, with a notable concentration among a small group. Payments increased annually until the pandemic’s onset, which coincided with a substantial decrease. Further research is needed to explore the implications of these financial interactions on clinical practice and patient care in Japan.

Retraction: Tongyi Lu, Binhua Wu, Yunfei Yu, Wenhui Zhu, Simin Zhang, Yinmei Zhang, Jiaying Guo, Ning Deng. Blockade of ONECUT2 expression in ovarian cancer inhibited tumor cell proliferation, migration, invasion and angiogenesis. Cancer Sci. 2018; 109: 2221-2234. https://doi.org/10.1111/cas.13633.

The above article published online on 08 May 2018 in Wiley Online Library (wileyonlinelibrary.com), has been retracted by agreement between the journal Editor-in-Chief, Masanori Hatakeyama, the Japanese Cancer Association and John Wiley and Sons Ltd. The retraction has been agreed upon following an investigation into concerns raised by a third party, which identified multiple duplications and splicing in Figures3, 5 and 6 in the article. Although the authors corrected some of these images after repeating the experiments (Correction: https://doi.org/10.1111/cas.15012), they failed to provide an unedited source image for Figure6 upon request or a satisfactory explanation. Given the number and extent of the identified issues, the editors have lost confidence in the data and have therefore decided to retract it. The authors were informed of the decision to retract but remained unresponsive.